A sensor network may include distributed autonomous sensors. Uses of sensor networks include but are not limited to military applications, industrial process monitoring and control, machine health monitoring, environment and habitat monitoring, utility usage, healthcare and medical applications, home automation, and traffic control. A sensor in a sensor network is typically equipped with a communications interface, a controller, and an energy source (such as a battery).
A sensor typically measures a physical quantity and converts it into a signal that an observer or an instrument can read. For example, a mercury-in-glass thermometer converts a measured temperature into expansion and contraction of a liquid that can be read on a calibrated glass tube. A thermocouple converts temperature to an output voltage that a voltmeter can read. For accuracy, sensors are generally calibrated against known standards.
Detecting and managing stress is a significant problem in modern-day medicine. If fact, many doctors argue that stress and stress-related symptoms are a major cause of death. Consequently, methods and systems for modeling, measuring, and monitoring stress in a person provide significant health benefits.